The present invention relates generally to the field of reciprocating mechanisms, and more particularly, is directed to a stroke adjustment system to vary the stroke of a piston while the apparatus is in full operation.
The present invention is directed to a running stroke adjustment for reciprocating apparatus such as proportioning pumps, coal stokers, container fillers, reciprocating engines and the like wherein an eccentric connection is commonly employed to transmit rotary motion into reciprocating motion through a crank. In most prior art reciprocating pump mechanisms, the pump eccentric could not be adjusted and the stroke of the piston was not readily varied. Accordingly, only a fixed output or capacity could usually be designed in each unit.
More recently, when the need for stroke adjustment and variable output became desirable, other workers in the field attempted to develop suitable mechanisms to facilitate stroke adjustment for reciprocating mechanisms to meet the growing need. Particularly, in U.S. Pat. No. 3,398,691, a volume controlled pump was disclosed which included an external handle to rotate an adjusting shaft which inturn rotated a pinion for stroke adjustment purposes. An oblique shaft member formed an eccentric shaft and was movable for pump volume variation purposes. Another stroke adjustment apparatus was developed in U.S. Pat. No. 2,346,964 wherein a head was slidably mounted in a guideway. A slidable block was movable alson the guideway upon turning an external handwheel to provide stroke adjustment and consequently also to provide volume control.
In U.S. Pat. No. 3,119,280, a reciprocating pump with external knob adjustment was disclosed in combination with a gear linkage to adjust pump stroke length. In U.S. Pat. No. 3,698,288, a variable metering pump was disclosed which utilized a crank having offset means to vary the length of the stroke.
While these prior developments in the art have generally been directed to solve the same problem with which the present application is concerned, the heretofore developed mechanisms were all complicated in nature and expensive in construction. Additionally, some suffer from deficiencies such as the inability to vary stroke adjustment while the mechanism is in operation.